Method of transferring photosensitive material and apparatus used therefor

ABSTRACT

A method and apparatus for transferring a strip-form photosensitive paper material comprising mounting a feed roller on an upstream side of an exposure table and a transferring roller on a downstream side of the exposure table and intermittently transferring photosensitive paper material onto the exposure table only in predetermined feed size, characterized by measuring, in advance, a feed size of the photosensitive paper material based on a number of revolutions of the feed roller and a feed size of the photosensitive paper, based on number of revolutions of the transferring roller, and compensating for the number of revolutions given to both rollers in order to prevent an error generated between the photosensitive paper feed sizes and an exposure table having upstream feed rollers and downstream transfer rollers and control means for measuring and feed the photosensitive paper material.

TECHNICAL FIELD

The present invention relates to a method of transferring photosensitivematerial and apparatus used therefor. More particularly, the presentinvention relates to a method of transferring strip-form photosensitivematerial (hereinafter called “paper”) and an apparatus used thereforwhich can transfer the paper in such a manner to prevent a differencebetween the predetermined feed size, in particular, when the paper headend portion is sent out only by feed rollers (the size is a print sizecorresponding to one image which is intermittently sent by atransferring device. If, for example, film has mixed images of varyingprint sizes, such as full size or panorama size, each adequatepredetermined length of the paper, corresponding to the relevant oneimage, is sent out, and the feed size, when the paper head end portionis transferred after being sandwiched between transferring rollers, andwith back tension between the transferring rollers and the feed rollers.The present invention also relates to a method of transferring the paperand apparatus used therefor, which can accurately form a punch hold onthe paper for serving as a positioner when the photosensitive materialis transferred.

BACKGROUND ART

FIG. 8 shows one example of a photo-processing apparatus. Thisphoto-processing apparatus comprises a printing part 1 for printingimages on the paper and a processing part 2 for carrying out treatments,such as development to the printed paper.

In the printing part 1, there are equipped, along the paper transferringroute, a loading part 3 for transferring the paper to the exposuretable, an exposure table 4 for exposing and printing the photosensitivepaper, an advance part 5 for accurately transferring a predeterminedlength of the photosensitive paper, a paper transferring part 6 and astock tank part 7 which can form loops for adjusting the advance of thephotosensitive paper to be sent to the processor part 2, and an outletpart 8. In the processing part 2, there are provided a processor rackpart 9 in a treatment tank for carrying out color development,bleaching, and fix stabilization; a dryer part 10 in a drying tank fordrying the photosensitive paper; and a cutter part 11 in the vicinity ofthe outlet.

In such photo-processing apparatus, a paper-transferring apparatus isinstalled for transferring the photosensitive paper, by means of aplurality of rollers, from the process of pulling out a proper amount ofphotosensitive paper, wrapped and held around a roll magazine (notshown), in a roll form, until the process of finishing the paper into aprint, at the processing part 2 are carried out. As shown in FIG. 1A,particularly, the photosensitive paper P sent out onto the exposurestand 4 must be transferred exactly by one print size (a predeterminedpaper feed size) in view of the fact that an image is printed on it.Therefore, in FIGS. 1A and 1B, the feed roller 22 mounted on theupstream side of the exposure stand 4 and the transferring roller 23 onthe downstream side of the transferring route of paper P are bothconnected to a pulse motor, and are given precisely same number ofrevolution so that the feed size can be controlled with back tensiongiving to the paper.

As shown in FIG. 1A, the feed size of the paper P is controlled based onthe number of revolution of the feed roller 22 until the head end P1 ofthe paper P is sandwiched between transferring rollers 23, and as shownin FIG. 1B, the feed size, after the paper is sandwiched betweentransferring rollers 23, is controlled based on the number of revolutionof transferring rollers 23.

Consequently, controlling the number of revolution of both rollers inthe same manner gives rise to a problem that the paper is unable to betransferred exactly in the predetermined size if there is any error inthe out side diameters of both rollers.

The difference of outside diameter of both rollers is caused not only byprocessing problems but also by the fact that the outside diameter ofthe feed roller 22 is intentionally made smaller than that of thetransferring roller 23 in order to provide back tension to the paperafter it is held between the transferring rollers. In the latter case,in particular, there are rised problems of various inconveniences suchas positional discrepancy of the image in the finished print ordeviation of the cut size because dimensional deviation becomesremarkable.

There is also a problem of generating waste at the paper head endportion if the paper is exposed after the head end of the paper is heldbetween the transferring rollers.

In addition, there can be assumed a case in which the number ofrevolution of the feed roller and that of the transferring roller areindividually set in advance to feed the predetermined size because ofthe difference in the outside diameter between the feed roller and thetransferring roller. There is, however, a case in which the paper issandwiched between the transferring rollers before the predeterminedsize is completely sent out with the feed roller only. In such case, thepredetermined size is unable to be sent out unless specialcountermeasures are taken.

In the above-mentioned paper-transferring apparatus, in general, inorder to accurately send the paper to each section stated above, punchholds are drilled near the edge between image frames of the paper, thepunch holes are detected at the necessary section by a sensor, andpositions of stopping and cutting are determined. Consequently, theaccuracy is required for the punch hole position, and back tension isapplied to the paper or the paper feed is controlled by a pulse motor toprevent variation of the punch hold position.

However, even if the paper is given back tension or feed-controlled, asdescribed above, there is a problem of inability to improve thepositional accuracy of the punch hole as required because the punch holeis drilled with the paper head end not held between the transferringrollers when the paper head end is being exposed. That is, since thepaper is sent out to the punch unit by the strength of the paper only,it is difficult to push out and transfer the paper curled by thewrapping in the roll magazine, and, therefore, slack is unavoidablygenerated in the paper, and it is difficult to accurately arrange thepunch hole position. If the paper is transferred and processed in thepaper-transferring apparatus with the punch hole deviated, the deviationis generated in the image position in the finished print or defect isgenerated in the cut size.

Drilling punch holes with the head end held in order to eliminatevariation of the punch hole position at the head end generates a greatdeal of portions in which no punch hole is produced, resulting in lossof the paper.

In addition, in the above-mentioned photo-processing apparatus, ingeneral, a plurality of driving rollers are used and between respectivedriving rollers, a difference is generated in the roller outsidediameters due to processing errors, driving motor control methoddiffers, or roller material is different, thereby generating adifference in the feed rate of each driving roller.

While the apparatus is used over a long time, in each roller,contamination and wear gradually progress. The roller surface becomesslippery due to the contamination and the difference is also generatedin the roller outside diameter due to the variation of the degree ofwear, and as a result, a difference is generated in the feed rate ofeach driving roller.

If this error is left as it is, the paper is unable to be transferred inthe predetermined sie, and paper slacks or paper pull-out betweenrollers occurs, causing inconvenience, such as, deteriorated printquality, deviation of cut position or printing position, or paperjamming due to defective transportation.

Consequently, in order to absorb the error of the feed rate of eachdriving roller, there have been a method of measuring the feed rate perone rotation of each driving roller, comparing the measured value withthe theoretical value, increasing or decreasing the feed rate based onthe comparison results, and compensating for the error, and a method ofproviding a buffer to absorb the error (for example, a method ofintentionally slacking the paper and pulling it out when more than apredetermined slack volume is formed).

However, even if error is compensated for individual rollers, there is aproblem that it is extremely difficult to completely synchronize all therollers, and there is another problem that even if a buffer is provided,an apparatus for controlling the buffer is required and thus more costsor space are required.

Under the foregoing circumstances, it is an object of the presentinvention to provide a method of transferring a paper and apparatus usedtherefor which can constantly provide the predetermined feed sizewhichever feed roller or transferring roller with a different outsidediameter is driven.

More specifically, it is another object of the present invention toprovide a method of transferring the paper and apparatus used thereforwhich can form punch holes accurately in the paper for serving as apositioner during transferring.

Still another object of the present invention is to provide an apparatusof transferring photosensitive material which can apply proper tensionto the paper so that the paper traveling condition is good, and whichcan absorb the error of the feed rate caused by the processing error ofthe roller outside diameter so that strict roller processing accuracy isnot required but cost reduction can be achieved.

The paper-transferring method according to the first embodiment of thepresent invention comprises mounting a feed roller on an upstream sideand a transferring roller on a downstream side with an exposure tablelocated therebetween, and intermittently transferring a strip-form paperonto the exposure table only in the predetermined feed size, andcharacterized by measuring in advance a feed size of the paper based onnumber of revolution of the feed roller and a feed size of the paperbased on the number of revolution of the transferring roller andcompensating for the number of revolution given to both rollers in orderto prevent an error generated between both paper feed sizes.

The paper-transferring apparatus according to the first embodiment ofthe present invention comprises a feed roller mounted on an upstreamside and a transferring roller on a downstream side with an exposuretable located therebetween, and a control mechanism for controllingnumbers of revolution of the both rollers in order to intermittentlytransfer a strip-form paper onto the exposure table only by apredetermined size, and is characterized in that the control mechanismcompensates for the feed size of the paper based on the number ofrevolution of the feed roller and the feed size of the paper based onthe number of revolution of the transferring paper so as to prevent anydifference from being generated between the two feed sizes.

In addition, the paper-transferring method according to the firstembodiment of the present invention comprises providing a feed rollermounted on an upstream side and a transferring roller on a downstreamside with an exposure table located therebetween and a control mechanismfor controlling numbers of revolution of the both rollers in order tointermittently transferring a strip-form paper onto the exposure tableonly by a predetermined size, characterized by controlling thepredetermined feed size based on the number of revolution of the feedroller until a paper head end is sandwiched between the transferringroller and controlling the predetermined feed size based on the numberof revolution of the transferring roller after the paper is sandwichedbetween the transferring roller; and if the predetermined size of thepaper is unable to be sent out by the feed roller only and is sandwichedbetween the transferring roller, stopping the rotation of the feedroller just before the paper is sandwiched between the transferringroller, computing the size short for the predetermined feed size bycomputing the feed size which the feed roller has sent, computing thenumber of revolution of the transferring roller corresponding to thecomputer value, and rotating the transferring roller only as much as thecomputed value.

The paper-transferring apparatus according to the first embodiment ofthe present invention comprises a feed roller mounted on an upstreamside and a transferring roller on a downstream side with an exposuretable located therebetween, and a control mechanism for controllingnumber of revolutions of the both rollers in order to intermittentlytransferring a strip-form paper onto the exposure table only by thepredetermined size, and is characterized in that the control mechanismcontrols the predetermined feed size based on the number of revolutionof the feed roller until a paper head end is sandwiched between thetransferring roller and controls the predetermined feed size based onthe number of revolution of the transferring roller after the paper issandwiched between the transferring roller; and if the predeterminedsize of the paper is unable to be sent out by the feed roller only andis sandwiched between the transferring roller, the control mechanismstops the rotation of the feed roller just before the paper issandwiched between the transferring roller, and computes the size shortfor the predetermined feed size by computing the feed size which thefeed roller has sent, computes the number of revolution of thetransferring roller corresponding to the computed value, and rotates thetransferring roller only as much as the computer value.

The paper-transferring method according to the second embodiment of thepresent invention comprises sending a strip-form paper stored and heldwith the paper being wrapped in a roll form onto an exposure table by afeed roller and transferring the paper with the head end beingsandwiched between the transferring roller, and is characterized bytransferring the paper with the paper mask mounted on the exposure tablebeing closed until a head end of the paper is sandwiched between thetransferring roller.

It is preferable to keep the paper-transferring speed slower than thenormal transferring speed till the paper head end is sandwiched betweenthe transferring roller.

In addition, even if the paper mask is not held closed, it is preferableto only keep the paper-transferring speed slower than the normaltransferring speed.

It is preferable to use the paper-transferring method in apaper-transferring apparatus which sends a strip-form paper onto anexposure table by a feed roller, forms punch holes with a punch unit,and transfers the paper with the head end being sandwiched between atransferring roller.

A paper-transferring apparatus according to the second embodiment of thepresent invention comprises an exposure table for printing and exposingthe paper, a paper mask mounted on the exposure table, a feed rollerdisposed on an upstream side of the exposure table and a transferringroller disposed on a downstream side of the exposure table, and ischaracterized in that the paper mask is kept closed when a head end ofthe paper is sent out onto the exposure table with the feed roller untilthe head end is sandwiched between the transferring roller.

It is preferable to keep the paper-transferring speed slower than thenormal transferring speed when the head end of the paper is sent outonto the exposure table with the feed roller until the head end issandwiched between the transferring roller.

In addition, even if the paper mask is not held closed, it is preferableto only keep the paper-transferring speed slower than the normaltransferring speed.

It is preferable to have a punch unit for forming punch holes in thepaper between the exposure table and the transferring roller.

A paper-transferring apparatus according to the third embodiment of thepresent invention comprises a plurality of driving rollers arrangedalong a transferring route for transferring a strip-form paper via anexposure table, and is characterized in that the relative difference ofcapabilities of feed rate in the adjoining driving rollers is adjustedto be smaller for driving rollers on an upstream side than for drivingrollers on a downstream side.

It is preferable to adjust relative difference of number of revolutionin adjoining driving rollers to be smaller for driving rollers on anupstream side than for driving rollers on a downstream side if rollerdiameters of the adjoining driving rollers are nearly equal.

It is preferable to adjust relative difference of roller diameter inadjoining driving rollers to be smaller for driving rollers on anupstream side than for driving rollers on a downstream side if numbersof revolution of the adjoining driving rollers are nearly equal.

In addition, it is preferable that the adjoining driving rollers arenext to each other via the exposure table.

It is also preferable that the driving roller on the upstream side ofthe adjoining driving rollers is formed with the material with smallerfrictional resistance than that of the driving roller on the downstreamside and the paper is designed to slip over the driving roller surfaceon the upstream side if the driving roller on the upstream side of theadjoining driving rollers is disposed so as to come in contact with abase surface of the paper.

Or, it is preferable to form the driving roller on the downstream sideof the adjoining driving rollers with the material of smaller resistancethan that of the driving roller on the upstream side and the paper isdesigned to slip over the driving roller surface on the downstream sideif the driving roller on the downstream side of the adjoining drivingrollers is disposed so as to come in contact with a base surface of thepaper.

Furthermore, it is preferable to be constructed in such a manner that adriving roller of the driving rollers disposed so as to come in contactat least with an emulsion surface of the paper has a torque limiterwhich is designed to operate to cause the driving roller to slip at adriving source before the paper causes slippage on a surface of thedriving roller.

In the method of transferring the paper according to the firstembodiment of the present invention and the apparatus used therefor, thefeed size of the paper based on the number of revolution of the feedingroller is controlled to achieve the same paper feed size based on thenumber of revolution of the transferring roller by measuring andcompensation. Therefore, the predetermined feed size same as that afterthe paper is sandwiched between transferring roller can be accuratelytransferred when the paper is sent out only by the feed roller beforethe paper head end is sandwiched between the transferring roller.

Further, the numbers of revolution of the feed roller and thetransferring roller are independently set in advance to send thepredetermined feed size, and when the paper is sandwiched between thetransferring roller before the predetermined feed size have been sentout, the number of revolution equivalent to that short for thepredetermined feed size is given to the transferring roller to send thepredetermined feed size.

In the method for transferring the paper and the apparatus used thereforaccording to the present invention, the paper is guided to a paper maskwith the paper mask being closed while the paper head end is sent outonto the exposure table by the feed roller and is sandwiched between thetransferring roller, thereby preventing slack of the paper on theexposure table.

By keeping the transferring speed of the feed roller slower than thenormal transferring speed while the paper head end is sandwiched, theforce for pressing the paper is thoroughly transmitted to the head endof the paper to prevent paper slack.

Paper slack can be prevented more accurately by sending the paper withthe paper mask closed while the paper head end is sandwiched as well asby keeping the transferring speed of the feed roller slower than thenormal transferring speed.

Moreover, in the paper-transferring apparatus according to the thirdembodiment of the present invention, if one driving roller of aplurality of driving rollers of the paper-transferring apparatus isdesignated to a main roller, the main roller does not slip and otherdriving rollers mounted on the upstream side or on the downstream sideof the main roller are likely to be easier to slip than the main roller.If the feed rate of the driving roller on the upstream side of the mainroller is reduced, the main roller tries to feed the paper more than theupstream driving roller, and the upstream driving roller slips. It is,therefore, able to apply tension to the paper between the main rollerand the upstream driving roller. If the feed rate of the driving rolleron the downstream side of the main roller is increased, the feed ratewhich the main roller feeds to the downstream driving roller decreases.Then, the downstream driving roller slips, and it is, therefore, able toapply tension to the paper between the main roller and the downstreamdriving roller.

The capability of the feed rate of each driving roller can be adjustedby providing a difference in the outside diameter of each driving rolleror by providing a difference in the number of revolution of each drivingroller.

It is also possible to easily cause the paper to slip on the outercircumferential surface of the roller by forming the driving roller withthe material with a small frictional coefficient.

The driving roller mounted at the position in contact with the emulsionsurface of the paper can be slipped without rubbing the paper surface byinstalling the torque limiter in such a manner that the driving rolleris allowed to slip at the driving source.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A and FIG. 1B are an operational explanatory view of oneembodiment of a paper-transferring apparatus according to the invention;

FIG. 2 and FIG. 3 are explanatory views showing a compensation method ofthe paper-transferring apparatus of the invention;

FIGS. 4A and 4B are explanatory views of another embodiment of thepaper-transferring apparatus according to the invention;

FIG. 5 is an operational explanatory view of one embodiment of thepaper-transferring apparatus according to the second embodiment of theinvention;

FIGS. 6A and 6B are operational explanatory views of another embodimentof the paper-transferring apparatus according to the second embodimentof the invention;

FIG. 7 is an explanatory view of the third embodiment of thepaper-transferring apparatus according to the invention; and

FIG. 8 is an explanatory view showing one example of construction of aphoto-processing apparatus.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring now to the drawings, the paper-transferring method of thepresent invention and the apparatus used therefor will be described indetail hereinafter.

FIG. 1 is an operational explanatory view of one embodiment of thepaper-transferring apparatus according to the invention.

In FIG. 1A, paper P is sent out onto an exposure table 4 with a papermask 21 closed, and a head end P1 is transferred while sandwichedbetween the exposure table 4 and the paper mask 21. Keeping the papermask 21 closed until the paper head end P1 reachers a transferringroller 23 can prevent paper P from being slackened.

Feed roller 22 and transferring roller 23 are driven by motors, such as,pulse motors, which can provide accurate number of revolution. Forexample, in the case of the pulse motor, by controlling the number ofpulses given, an accurate number of revolution can be provided. Becausethe transferring apparatus, according to the present invention, mustsend, exactly by one print size intermittently onto the exposure table4, this kind of pulse motor and the like are used.

As shown in FIG. 1A, because the paper is sent out only by the feedroller 23 until the paper head end P1 is sandwiched between thetransferring roller 23, the feed size is controlled by the number ofrevolution of the feed roller 22. Because, after the paper head end issandwiched between the transferring roller 23, the transferring roller23 pulls the paper and the feed roller 22 slips to provide tension tothe paper, the feed size is controlled by the number of revolution ofthe transferring roller 23.

The present invention is designed to correct the feed size of the feedroller 22 and the feed size of the transferring roller 23 to be constanteven when the outside diameters of the feed roller 22 and thetransferring roller 23 differ from each other connection is carried outby measuring the actual feed sizes of the feed roller and thetransferring roller. The difference of the outside diameters includemanufacturing errors in addition to planned design difference.

Referring now to FIGS. 2 to 3, one example of measuring and correctionis described.

First of all, as shown in FIG. 2, correction of the feed size of thepaper head end sent out only by the feed roller 22 to be constant iscarried out by providing in advance marks M1, M2 (for example, smallholes) for indicating a constant length, L, for reference on the sideface, or on the upper surface of the exposure table 4 and by giving thefeed roller 22 the number of revolution for sending the paper only bythe length L estimated from the outside diameter of the feed roller 22.Based on whether the paper reaches the distance L as predicted, thenumber of revolution is increased or decreased to determine the numberof revolution which can feed exactly the reference length L. If a pulsemotor is used, the number of pulses is determined.

The comparison with the above-mentioned reference length L is carriedout by measuring the interval of the punch holes drilled by a punch unit24. That is, as shown in FIG. 3, the head end portion A of paper A isthe portion sent out only by the feed roller 22. The number ofrevolution (or the number of pulses) is adjusted so that the interval ofthe punch holes located at this section A becomes the reference distanceL.

Then, correction of the feed size, after the paper is sandwiched betweenthe transferring roller 23 is carried out by measuring the interval ofpunch holes formed at section B which is not subject to the influence ofthe feed roller 23 as shown in FIG. 3. If this interval N is comparedand is found to be smaller than the reference length L, positivecorrection is carried out, and if it is larger than the reference lengthL, negative correction is carried out.

Further, as described above, if the predetermined size is unable to besent only by the feed roller 22 even with both corrected rollers 22, 23,that is, if the paper of one print size length is unable to be sent andis sandwiched between the transferring roller 23, the remainder sizemust be transferred by the transferring roller 23.

For example, if the print width to be printed in the exposure area E isF, as shown in FIG. 4A, the feed roller 22 and the transferring roller23 must intermittently send the paper exactly as much as the print sizeF.

Because the paper head end P1 is sent by the feed roller 22 until it issandwiched between the transferring roller 23 at the point A, this printsize F is controlled by the number of revolution of the feed roller 22.

However, if only the size L1 is sent to the exposure area E when thepaper head end P1 reaches the point C, the remainder size L2 must besent by the transferring roller 23.

Therefore, in such event, how much the transferring roller 23 must berotated additionally is computed as follows.

First of all, in FIG. 4A, the feed roller 22 is temporarily stopped whenthe paper head end P1 reaches the point A. Then, how many times theroller has been rotated to this point after the feed roller 22 finishessending the print size of one print before is measured. This measurementis carried out by determining the number of pulses given to the motorbefore this point if the control mechanism uses a pulse motor, and thefeed size L1 which the feed roller 22 has sent is computed from thenumber of revolution of the feed roller 22. The remaining size L2 iscomputed by the following formula. That is,

L 2 (remainder size)=F (print size)−L 2 (feed size of the feed roller).

Then, let the size which the transferring roller 23 can feed in onerotation by S, the number of revolution of the transferring roller 23required for sending the remaining size L2 is expressed by

Number of revolution of the transferring roller 23=L2/S.

As described above, even when one print size is delivered from the feedroller 22 to the transferring roller 23 on the halfway of feeding oneprint size, it is possible to send exactly one print size.

Referring now to one pulse as an example, this is discussed morespecifically, because the number of revolution is proportional to thenumber of pulses when both rollers 22, 23 are driven by a pulse motor.

For example, assume that if the paper head end P1 is sent only by thefeed roller 22, giving one pulse to the feed roller 22 sends the paper 1mm. On the other hand, after the head end P1 is sandwiched between thetransferring roller 23, one pulse is given to both the transferringroller 24 and the feed roller 22, and assume that the feed rate of thepaper in this event is 1.5 mm.

Now, let the print size F of the print to be printed be 100 mm and thenumber of pulses given to the feed roller 22 be P1 when the paper headend reaches the point A, the number of pulses P2 to be given to thetransferring roller 23 is found by

P 2=(100−1×P 1)/1.5

Referring now to FIGS. 5 to 6, the method of transferring paper and theapparatus used therefor according to the second invention will beexplained.

In FIG. 5, the paper P is sent out onto the exposure table 4 by the feedroller 32 with the paper mask 31 being closed. If it is sent out withthe paper mask 31 not being closed, the paper P slackens and bulges asshown with an alternate long and two short dashed lines. Because thisbulging condition depends on the winding diameter when the paper iswound and held in a roll form in the paper magazine, the condition ofpaper P is not constant when its head end P1 reaches the punch unit 34,and it is unable to keep the positional accuracy of the punch hole.However, because driving the feed roller 32 with the paper mask 31 beingclosed allows the paper mask 31 to play a role of a guide and the paperhead end P1 to reach the punch unit 34 under a stable condition, it ispossible to keep the positional accuracy of the punch hole.

In the paper-transferring apparatus according to the present invention,the transferring speed of the feed roller 32 is designed to be slowerthan the normal transferring speed until the paper head end P1 issandwiched between the transferring roller 33. Specifically, thetransferring speed is about 20-70% of the normal transferring speed,preferably about 50%, and for example, if the normal transferring speedis 400 mm/sec, it is preferable to be about 200 mm/sec. By doing so, thepaper pressing force can be transmitted far enough to the top end of thepaper and the paper can be sent out comparatively straight.

The above-mentioned two methods might be implemented separately but itis preferable to be implemented together, and with this implementation,the positional accuracy of the punch hole can be further improved.

If the paper feed rate is particularly small, for example, when sendingthe paper head end, or when a plurality of punch holes are drilled in ashort pitch (for example, 2 mm to 4 mm) to mark the paper with border orborderless, setting the motor acceleration slower than the normalacceleration can minimize the slip between the paper and the feed rollerat the start-up of the motor, and the paper can be accuratelypositioned. Specifically, the acceleration is preferably about 40% ofthe normal acceleration, and for example, if the normal acceleration is0.1716 pulses/mmsec² in a pulse motor, it is preferable to reduce it to0.039 pulses/mmsec².

In a method for transferring paper and an apparatus used thereforaccording to the present invention, closing the paper mask 31, reducingthe transferring speed, and making the feed rate of the feed rollerand/or transferring roller controllable can achieve further effects andcan eliminate the deviation of punch holes, thereby enabling cutting athigh dimensional accuracy.

For example, in FIG. 6A, the paper P is sent by the feed roller 32 untilthe head end P1 is sandwiched between the transferring roller 33. On thecontrary, in FIG. 6B, because the feed rate of the paper P is determinedprimarily by the number of revolution of the transferring roller 33 andback tension is given to paper P after the paper P is sandwiched betweenthe transferring roller 33, there is a case in which the feed roller 32is in the slipping condition.

Therefore, as shown in FIG. 3, the respective numbers of revolution arecontrolled so that the intervals L, N of the punch holes drilled in thepaper P become same at the paper top end portion A influenced by thefeed roller 32 and the portion B thereafter. The control of the numberof revolution is carried out by measurement and correction.

Referring now to FIG. 7, the paper-transferring apparatus according tothe third embodiment will be described.

In FIG. 7, numeral 41 denotes a main roller, 42 a first roller, and 43 asecond roller. The paper P is transferred from the first roller 42 tothe main roller 41, and then to the second roller 43.

The present invention is characterized by adjusting the capability ofthe feed rate to be relatively different in adjoining driving rollers sothat tension is given to the paper located between adjoining drivingrollers. Consequently, the word “upstream” or “downstream” in the claimrefers to the main roller 41 as the downstream side and the first roller42 as the upstream side when the main roller 41 and the first roller 42are compared. If the main roller 41 and the second roller 43 arecompared, the main roller 41 is on the upstream side and the secondroller 43 is on the downstream side. In this embodiment, in order toclarify the explanation, with the main roller 41 as a reference,explanation will be made with the first roller 42 designated as theupstream driving roller and the second roller 43 as the downstreamdriving roller. The first roller 42 is in contact with the base surfaceof the photosensitive material, while the second roller 43 and the mainroller 41 are in contact with the emulsion surface of the photosensitivematerial.

The main roller 41 is formed with material with a large frictionalcoefficient, for example, rubber (urethane rubber, silicone rubber,etc.) So that the paper does not slip on its outer circumferentialsurface.

The first roller 42 and the second roller 43 apply tension to the paperby slipping against the main roller. Examples of slipping method includea method for slipping the paper on the roller outer circumferentialsurface or a method for rotating (slipping) the rollers themselves at anumber of revolution different from the number of revolution transmittedby the driving source when torque, more than a specified degree, isapplied.

When the roller, itself, is slipped, the first roller 42 locatedupstream with respect to the main roller 41 rotates (slips) at a highernumber of revolution than the number of revolution of the driving sourcetransmits and the second roller 43 on the downstream side rotates(slips) at a lower number of revolution.

Which method should be adopted shall be determined by whether thedriving roller is in contact with the paper emulsion surface or with thebase surface. That is, because at least the driving roller in contactwith the emulsion surface must not slip on the emulsion surface, theroller itself must be designed to slip. This is because rubbing theemulsion surface causes a problem of photograph quality. However, anymethod might be used for the rollers in contact with the base surface.

In FIG. 7, the side facing the exposure table 4 is the base surface, andthe upper side is the emulsion surface A. Consequently, the first roller42 is a roller in contact with the base surface, and thus is formed withthe material with a small frictional coefficient such as stainlesssteel, surface-treated aluminum (alumite-treatment), iron (plating),resin, etc. so that the paper slips on the surface. The second roller 43is a roller in contact with the emulsion surface and thus is formed withrubber of a large frictional coefficient (urethane rubber, siliconerubber, etc.) so that the paper does not slip on the surface. For atorque limiter, a frictional type torque limiter is preferable.

The capability of the feed rate of the upstream first roller 42 isadjusted to be smaller than the feed rate of the main roller 41 and thecapability of the feed rate of the downstream second roller 43 isadjusted to greater than the feed rate of the main roller 41. Examplesof a method for adjusting in this way include a method for adjusting theoutside diameter of the driving roller, a method for adjusting thenumber of revolution, etc.

For the method to adjust the outside diameter of the driving roller, forexample, it is determined that the outside diameter of the main roller41 is 100 mm, the outside diameter of the first roller 42 is 99 mm, andthe outside diameter of the second roller 43 is 101 mm. Giving the samenumber of revolution to each of the driving rollers 41, 43, and 43 underthis condition causes the upstream first roller 42 to be 99% of the feedrate of the main roller 41, pulling the paper by 1%. The downstreamsecond roller 43 becomes 101% of the feed rate of the main roller 41,also pulling the paper by 1%. In this way, it is preferable to determinethe outside diameters of the first roller 42 and the second roller 43 soas to achieve 0.2-5% slippage in view of the processing limit(dimensional variations by processing). This is because if the slippageis 0.2% or less, the paper tension is short and if it is 5% or more, thepaper slips too much.

For a method of adjusting the number of revolution, there is a method ofusing, for example, a pulse motor, adjusting the number of pulses to begiven using the acceleration or maximum speed, and decelerating thefirst roller 42 and accelerating the second roller 43, respectively,with respect to the main roller 41.

The main roller might be selected from either of the adjoining drivingrollers or provided separately from them. When a plurality of mainrollers are mounted, it is preferable to use the gear and chain so thatthe feed rate of each main roller becomes equal. It is also preferableto keep the diameter and the number of revolution of each main rollerequal.

As described above, the method of transferring the paper and theapparatus used therefor according to the first invention is able toaccurately transfer the same size as that after the paper is sandwichedbetween the transferring roller even when the paper head end is not yetsandwiched between the transferring roller and is sent out only by thefeed roller, because the paper feed size, based on the number ofrevolution of the feed roller, is controlled to be the same as the paperfeed size based on the number of revolution of the transferring roller.This achieves remarkable effects particularly when there is a differencein outside diameter between the feed roller and the transferring roller.

The predetermined feed size which the transferring apparatus of thefirst embodiment intends to intermittently send is, for example, oneprint size, and even when the head end of the paper is delivered fromthe feed roller to the transferring roller in the midst of feeding oneprint size, the remaining feed size is computer from the feed size ofthe feed roller and the remaining feed size is controlled to be sent bythe transferring roller, and it is possible to constantly maintain thepredetermined feed size.

Consequently, even the portion before the paper head end, which issandwiched between the transferring roller, can be used for printing inthe same manner as the portion after that which is sandwiched by thetransferring roller; the loss of the portion can be eliminated and, atthe same time, the positional deviation of the image in the finishedprint, or deviation of the cut size, can also be eliminated.

The method of transferring the paper and the apparatus used thereforaccording to the second embodiment can eliminate loss of the paper headend and maintain the positional accuracy of the punch hole accurately,because paper slacking and bulging on the exposure table are prevented,even if the paper head end is not sandwiched between the transferringroller by closing the paper mask and/or by controlling the transferringspeed of the feed roller to be slower than the normal transferring speeduntil the paper head end is sent out onto the exposure table by the feedroller and is sandwiched between the transferring roller.

In addition, the paper transferring mechanism in the photo-processingapparatus, according to the third embodiment is able to constantly applysuitable tension to the paper and is able to prevent focus deviationcaused by paper slacking, stopping position deviation, print qualitydegradation, and paper jamming at the transferring route. Because it isdesigned to allow the paper, or the driving roller itself, to slip andapply tension to the paper, processing errors of the outside diameter ofthe driving roller can be absorbed, a conventional mechanism for errorcorrection or a buffer is no longer required, the construction becomessimple, and cost reduction can be achieved.

Using a torque limiter for the driving roller in contact with theemulsion surface to allow the driving roller to slip at the drivingsource and to prevent slip on the roller surface can prevent detrimentaleffects on the photo quality.

Industrial Applicability

The method of transferring the paper and the apparatus used thereforaccording to the present invention can accurately transfer the paperexactly as much as the predetermined size and are very useful, inparticular, for the photo-processing apparatus equipped with apaper-transferring mechanism.

I claim:
 1. A method for transferring a strip-form photosensitive papermaterial comprising: mounting a feed roller on an upstream side of afeed path of said material and a transfer roller on a downstream side ofsaid feed path with an exposure table located on said path therebetweenand intermittently transferring said photosensitive material onto saidexposure table in a predetermined feed size length of said paper to betransferred, measuring in advance a feed size of the paper to betransferred based on number of revolution of the feed roller and a feedsize of the paper to be transferred based on number of revolutions ofthe transferring roller and compensating for the number of revolutionsto be given to each of said rollers for preventing an error in materiallength generated between paper feed lengths.
 2. An apparatus fortransferring a strip-form photosensitive paper material comprising afeed roller mounted on an upstream side of a feed path of said materialand a transferrring roller on a downstream side of said feed path withan exposure table located therebetween, and a control mechanism forcontrolling numbers of revolution of said upstream and downstreamrollers in order to intermittently transferring a strip-form paper ontosaid exposure table by a predetermined length of said strip formmaterial, characterized in that said control mechanism compensates forthe feed size of the strip-form material based on the number ofrevolutions of the feed roller and the feed size of the strip form papermaterial based on the number of revolutions of the transferring stripform material so as to prevent any difference from being generatedbetween the two feed sizes.
 3. A method for transferring a strip-formphotosensitive material comprising providing a feed roller mounted on anupstream side and a transferring roller on a downstream side with anexposure table located therebetween and a control mechanism forcontrolling numbers of revolutions of said upstream and downstreamtransferring rollers in order to intermittently transfer strips ofstrip-form material onto the exposure table in a predetermined size,characterized by controlling predetermined feed size based on the numberof revolution of the feed roller until a paper head end is sandwichedbetween the transferring roller and controlling the predetermined feedsize based on the number of revolutions of the transferring roller afterthe paper is sandwiched between the transferring roller; and if thepredetermined size of the strip forming paper material is unable to betransferred by the feed roller only and is sandwiched between thetransferring rollers, stopping the rotation of the feed roller, justbefore the paper is sandwiched between the transferring rollers,computing the size of the strip-form material short for thepredetermined feed size by computing the feed size which the feed rollerhas sent, computing the number of revolutions of the transferring rollercorresponding to the computed value, and rotating the transferringroller only as much as the computed value.
 4. An apparatus fortransferring a strip-form photosensitive material along a transfer pathcomprising a feed roller mounted on an upstream side of said transferpath and a transferring roller on a downstream side of said transferpath with an exposure table located therebetween, and a controlmechanism for controlling the number of revolutions of said rollers inorder to intermittently transferring a strip-form photosensitive papermaterial onto the exposure table of a predetermined size, characterizedin that said control mechanism controls the predetermined feed size ofsaid strip form material based on the number of revolution of the feedroller until a paper head end is sandwiched between the transferringroller and controls the predetermined feed size based on the number ofrevolutions of the transferring roller after the strip-form papermaterial is sandwiched between the transferring roller, and if thepredetermined size of the strip-form paper material is not able to besend out by the feed roller and is sandwiched between the transferringroller and the control mechanism, stops rotation of the feed roller justbefore the paper is sandwiched between the transferring roller, and saidcontrol mechanism computes the size for the predetermined feed size bycomputing the feed size which the feed roller has transferred, computesthe number of revolutions of the transferring roller corresponding tothe computed value, and rotates the transferring roller only as much asthe computed value.
 5. An apparatus for transferring a strip-formphotosensitive material comprising a plurality of driving rollersarranged along a transferring path for transferring a strip-form papervia an exposure table, characterized in that the relative difference offeed rate in adjoining driving rollers is adjusted to be smaller fordriving rollers on an upstream end of said path than for driving rollerson a downstream end of said path, the driving roller on the upstreamside of the adjoining driving rollers is formed with a material withsmaller frictional resistance than the material of the driving roller onthe downstream side of the photosensitive material slips over thedriving roller surface on the driving roller on the downstream side andthe photosensitive material slips over the driving roller surface on theupstream side if the driving roller on the upstream side of theadjoining driving roller is disposed so as to come in contact with thebase surface of the paper.
 6. An apparatus for transferring a strip-formphotosensitive material comprising a plurality of driving rollersarranged along a transferring path for transferring a strip-form papervia an exposure table, characterized in that the relative difference offeed rate in adjoining driving rollers is adjusted to be smaller fordriving rollers on an upstream end of said path than for driving rollerson the downstream end of said path, wherein a driving roller on thedownstream side of the adjoining driving rollers is formed with thematerial of smaller resistance than that of the driving roller on theupstream side and the photosensitive material slips over the drivingroller surface on the downstream side if the driving roller on thedownstream side of the adjoining driving roller contacts a base surfaceof said strip form paper.
 7. An apparatus for transferring a strip-formphotosensitive material comprising a plurality of driving rollersarranged along a transferring path for transferring a strip-form papervia an exposure table, characterized in that the relative difference offeed rate in adjoining driving rollers is adjusted to be smaller fordriving rollers on an upstream end of said path than for driving rollerson the downstream end of said path, wherein a driving roller of thedriving rollers, disposed so as to come into contact at least with anemulsion surface of the paper, has a torque limitor for causing thedriving roller to slip as a driving source before the paper causesslippage on a surface of the driving roller.